In this study, we investigated the nitrate photolysis on photoactive TiO2 particles in the presence of SO2 through theoretic DFT calculation and in situ DRIFTS analysis, and found that in a clean atmosphere nitrate was oxidized to •NO3 radicals by the holes generated on the surface of TiO2 under solar irradiation, followed reactive nitrogen species generation via •NO3 radicals reduction by photoinduced electrons. After shifting to the SO2-polluted environment, •NO3 radicals preferentially reacted with abundant sulfites to significantly incre...
